Objective: To estimate the consumption level of four drugs in Beijing using wastewater-based epidemiology (WBE). Methods: The primary sludge from one large wastewater treatment plants (WWTPs) was collected in Beijing from July 2020 to February 2021. The concentrations of codeine, methadone, ketamine and morphine in the sludge were detected through solid-phase extraction-liquid chromatography-tandem mass spectrometry. The consumption, prevalence and number of users of four drugs were estimated by using the WBE approach. Results: Among 416 sludge samples, codeine had the highest detection rate (82.93%, n=345) with a concentration [M (Q₁, Q₃)] of 0.40 (0.22-0.8) ng·g^-1, and morphine had the lowest detection rate (28.37%,n=118) with a concentration [M (Q₁, Q₃)] of 0.13 (0.09, 0.17) ng·g^-1. There was no significant difference in the consumption of the four drugs on working days and weekends (all P values>0.05). Drug consumption was significantly higher in winter than that in summer and autumn (all P values <0.05). The consumption [M (Q₁, Q₃)] of codeine, methadone, ketamine and morphine in winter was 24.9 (15.58, 38.6), 9.39 (4.57, 26.72), 9.84 (5.18, 19.45) and 5.67 (3.57, 13.77) μg·inhabitant^-1·day^-1, respectively. For these drugs, there was an upward trend in the average drug consumption during summer, autumn and winter (the Z values of the trend test were 3.23, 3.16, 2.19, and 3.32, respectively and all P values<0.05). The prevalence [M (Q₁, Q₃)] of codeine, methadone, ketamine and morphine were 0.0056% (0.003 4%, 0.009 2%), 0.0148% (0.009 6%, 0.026 7%),0.0333% (0.0210%, 0.0710%) and 0.0072% (0.003 8%, 0.011 7%), respectively. The estimated number of drug users [M (Q₁, Q₃)] was 918 (549, 1 511), 2 429 (1 578, 4 383), 5 451 (3 444, 11 642) and 1 173 (626, 1 925),respectively. Conclusion: Codeine, methadone, ketamine and morphine have been detected in the sludge of WWTPs in Beijing, and the consumption level of these drugs varies in different seasons.
Humans ; Beijing ; Wastewater-Based Epidemiological Monitoring ; Sewage/analysis* ; Wastewater ; Ketamine/analysis* ; Codeine/analysis* ; Methadone/analysis* ; Water Pollutants, Chemical/analysis*

In recent years, as the third-generation of drugs, new psychoactive substances （NPS） have expanded rapidly and become a serious concern for China's anti-drug prevention and control system. As a new drug monitoring technology in the current anti-drug field, wastewater analysis is an objective, real-time, accurate, convenient and effective drug monitoring method. In recent years, it has gradually been applied to the monitoring of NPS. This study summarizes wastewater sample collection, target stability research, wastewater sample pretreatment, wastewater sample analysis methods, target NPS consumption calculations and actual monitoring applications, with a view to the construction of a monitoring system for NPS in wastewater, real-time and accurate grasp of information on the use of NPS in cities, the reflection of the actual consumption of different types of NPS and consumption trends in a short period of time, and prediction of the development trend of abused use, which is of great significance for combating NPS crimes, serving and guaranteeing the personal safety of the people, and maintaining social stability.
China ; Cities ; Illicit Drugs/analysis* ; Psychotropic Drugs/analysis* ; Wastewater/analysis* ; Water Pollutants, Chemical/analysis*